Directors are appointed by the President of the United States and confirmed by the Senate.[2][3] In theory, they serve ten-year terms unless they resign, die, or are let go; in reality, none have served a full ten years, except John Edgar Hoover and Robert Mueller, each of whom served longer than ten years. John Edgar Hoover, appointed by Calvin Coolidge to the predecessor office of Director of the Bureau of Investigation in 1924, was by far the longest-serving director; he held the position from its establishment under the current title in 1935 until his death in 1972 because there was then no law limiting service time. In response to Hoover's lengthy tenure, Congress imposed a term limit of ten years (waived by the Senate for Robert Mueller on July 27, 2011).[4] The current FBI director is James Comey, who assumed his position on September 4, 2013.

When the Bureau of Investigation (BOI) was established in 1908, its head was called the Chief of the Bureau of Investigation.[5] It was changed to the Director of the Bureau of Investigation since the term of William J. Flynn (1919–1921), and to its current name when the BOI was renamed FBI in 1935.